不同拓扑结构分子筛催化1-甲萘异构化-烷基转移耦合反应性能对比

Comparative study on the catalytic performance of zeolite catalysts with different topologies in 1-methylnaphthalene isomerization-transalkylation coupling reaction

以1-甲萘和均三甲苯为原料经固体酸催化的异构化-烷基转移耦合反应制备2-甲萘及二甲基萘。对MWW、BEA、FAU、MFI拓扑结构分子筛的催化性能进行对比研究,对反应机理进行探讨。采用XRD、BET、SEM、NH3-TPD、Py-FTIR及ICP等方法对催化剂结构物性进行了表征。与具有十元环特征孔道的MFI分子筛相比,具有十二元环特征孔道的MWW、BEA、FAU分子筛表现出更好的催化活性。BEA结构分子筛具有较高的二甲基萘选择性,而MWW结构分子筛具有较高的2-甲萘选择性并表现出优异的催化稳定性。在MWW结构分子筛中,HMCM-22的1-甲萘转化率达到70.27%,2-甲萘收率达到66.69%。而HMCM-56上则同时获得35.74%的2-甲萘收率和19.00%的二甲基萘收率。该研究为以中国丰富的碳十资源为原料制备高端聚酯单体2,6-二甲基萘开辟了颇具潜力的技术路线。

The isomerization-transalkylation coupling reaction between 1-methylnaphthalene and 1,3,5-trimethylbenzene was studied over zeolite catalysts to produce 2-methylnaphthalene and dimethylnaphthalene.The catalytic performance of zeolites with MWW,BEA,FAU and MFI topological structure was investigated and the reaction mechanism was discussed.The properties of zeolites were characterized by XRD,N2 adsorption-desorption,SEM,NH3-TPD,Py-FTIR and ICP.Compared with MFI zeolite with 10-membered ring channel,MWW,BEA and FAU zeolite with 12-membered ring channel showed better catalytic activity.BEA zeolite exhibited higher selectivity to dimethylnaphthalene,while MWW zeolites showed higher selectivity to 2-methylnaphthalene and the best catalytic stability.As a branch of MWW zeolites,HMCM-22 showed a 1-methylnaphthalene conversion of 70.27%and a 2-methylnaphthalene yield of 66.69%.It was worth noting that a relatively high yield of 2-methylnaphthalene(35.74%)and dimethylnaphthalene(19.00%)were obtained on HMCM-56 at the same time.This research has opened up a promising route using C10 aromatics as raw materials for the preparation of 2,6-dimethylnaphthalene,an important polyester monomer.